Hikvision NVR DS-7716ni-i4/16p Bricked

Hi, install the latest firmware to Hikvision NVR DS-7716ni-i4/16p (NVR_K51_BL_ML_STD_V4.40.015_200616) this worked without problems for 2 days, on the third day Nvr disappeared from the map, I have tried TFTP (ip-192.0.0.128 etc... without any result, my nvr was on firmware 3.4.92 before doing the update (All US Version). I have read in this forum that the new firmware is very heavy for the tftp, after many attempts with different tftp I got a light on the front panel to turn on (RX/TX) since previously only the power light turned on.
I have already tried various US and Uk firmware to try to get it back to life, equally unsuccessful except I repeat for the prompt (RX/TX) and every 10 min NVR does an automatic reboot...

Any recommendation?
Thanks in advance.